package main

import (
	"fmt"
	"log"
	"sort"
	"time"

	"git.milar.in/milarin/adverr"
	"git.milar.in/milarin/slices"
	"git.milar.in/nyaanime/logic"
	"git.milar.in/nyaanime/model"
)

func CheckTorrents() {
	log.Println("checking torrents")
	start := time.Now()

	torrents, err := GetTorrents()
	if err != nil {
		fmt.Println(adverr.Wrap("retrieving torrents failed", err))
		return
	}

	animeList, err := logic.GetAnimeListByAnimeID(logic.AnimeStatuses)
	if err != nil {
		fmt.Println(adverr.Wrap("retrieving anime list failed", err))
		return
	}

	// parse torrents
	parsedTorrentsByAnimeEp := ParseTorrentsByAnimeEp(torrents)

	// filter not on anime list
	animeListTorrents := FilterTorrentsByAnimeList(parsedTorrentsByAnimeEp, animeList)

	// filter essential properties
	essentialTorrents := FilterEssentialTorrents(animeListTorrents)

	// filter preferred properties
	preferredTorrents := GetTorrentsWithMaxPrioByAnimeEp(essentialTorrents)

	// information gathered for logging purposes
	downloadingEpisodes := map[model.AnimeEpisode]struct{}{}
	inCollectionEpisodes := map[model.AnimeEpisode]bool{}
	collectionPreferredTorrents := map[*model.ParsedTorrent]bool{}
	downloadedTorrents := map[model.AnimeEpisode]*TorrentPriority{}

	for animeEp, torrentPrio := range preferredTorrents {
		if IsCurrentlyDownloading(animeEp) {
			downloadingEpisodes[animeEp] = struct{}{} // debug output
			continue
		}

		props, inCollection := logic.GetAnimeEpProps(animeEp)

		inCollectionEpisodes[animeEp] = inCollection // debug output
		if inCollection {
			collectionPreferred := props.Priority >= torrentPrio.Priority
			collectionPreferredTorrents[torrentPrio.ParsedTorrent] = collectionPreferred // debug output
			if collectionPreferred {
				continue
			}
		}

		if err := DownloadTorrent(animeEp, torrentPrio.ParsedTorrent); err != nil {
			fmt.Println(fmt.Sprintf("could not download torrent %s", torrentPrio.ParsedTorrent.Torrent.ID), err)
		}

		downloadedTorrents[animeEp] = torrentPrio // debug output
	}

	duration := time.Since(start)

	ShowDebugInfo(
		parsedTorrentsByAnimeEp,
		animeListTorrents,
		essentialTorrents,
		preferredTorrents,
		downloadingEpisodes,
		inCollectionEpisodes,
		collectionPreferredTorrents,
		downloadedTorrents,
	)

	downloadedAnimeEpisodes := slices.OfMap(downloadedTorrents, func(animeEp model.AnimeEpisode, torrentPrio *TorrentPriority) model.AnimeEpisode {
		return animeEp
	})
	sort.Slice(downloadedAnimeEpisodes, GetAnimeEpisodesSortFunc(downloadedAnimeEpisodes))
	SendTelegramAnimeEpMessage(TelegramDownloadMessagePattern, downloadedAnimeEpisodes)

	log.Printf("check took %s. sleeping for %s\n", duration.Truncate(time.Millisecond), (PollRate - duration).Truncate(time.Millisecond))
}